1. PARAMOS The “paramos” constitute both a region and a vegetation type in the high equatorial Andes of northern South America (Ecuador, Colombia and Venezuela) (Vareschi 1988). They occur above 2,800 m elevation, and are characterized by highly diversified, complex genus Espeletia (Asteraceae), with life forms similar to those found within other genera of the same family in the Kilimanjaro (Senecio), Hawaii (Argyroxiphium). This life form is described as a giant rosette, with leaves covered with a dense, whitish hair layer. Leaves are not shed during senescence but remain adpressed to the succulent stem (marcescent leaves), providing thermal isolation to the water conducting tissue (Goldstein et al. 1991). Plants in this tropical alpine environment show adaptations to high irradiation, extreme diurnal temperature oscillations, and seasonal dry conditions (Monasterio and Sarmiento (1991).

2. Paramos: 10º N, 67W

6. Squeo F.A., Rada F., Azócar A., Goldstein G. (1991) Freezing tolerance and avoidance in high tropical Andean plants: is it equally represented in species with different plant height? Oecologia 86: 378-382. SpeciesLife-form Altitudinal distribution Arenaria jahnii Brake (Caryophyllaceae) cushion2400-4350 Azorella julianii Math (Apiaceae) cushion3500-4600 Lucilia venezuelensis Stmk. (Asterac.)cushion3650-4300 Castilleja fissifolia L.f. (Scrophulariaceae) perennial herb2000-4300 Geranium multiceps Tourez (Geraniaceae) perennial herb3000-4200 Senecio formosus H.B.K. (Asteraceae) perennial herb2800-4200 Draba chionophylla Blake (Cruciferae) small rosette4300-4600 Espeletia moritziana Sch. Bip. (Asteraceae) giant rosette3200-4400 Espeletia schultzii Wedd. (Asteraceae) giant rosette2600-4300 Espeletia spicata Sch. Bip. (Asteraceae) giant rosette3800-4300 Espeletia timotensis Cuatr. (Asterac.) giant rosette4000-4400 Hinterhubera lanuginosa Cuatr et Arist (Asterac)shrub3500-4200 Hypericum laricifolium Juess. (Guttiferae) shrub2200-4200 Polylepis sericeus Wedd. (Rosaceae)small tree2400-4600

8. Summary of morphological and physical characteristics of five Espeletia schultzii populations occurring along an elevation gradient (after Meinzer and Goldstein 1985) Elevation (m) Pith volume Leaf area PV/LA Pubescence thicknessLeaf absorptance (cm 3 ) (cm 2.10 4 ) (cm 3 cm- 2 ) (mm) 400-700 nm 2,600 (≈ 13ºC) 891.160.008 1.1 0.78 3,100 3360.960.039 1.6 0.74 3,550 4240.680.063 2.1 0.70 3,850 7020.640.116 2.3 0.67 4,200 (≈ 2.8ºC) 8730.480.179 2.6 0.69

12. Site characteristics where Espeletia species were studied to estimate the period of time during which the water removed from the pith could replace the water transpired (T) (Meinzer and Goldstein 1986) Paramo site Annual Mean and elevation precipitation temperature Species PV/LA ∆M T Hours (m) (mm) (ºC) (cm 3 cm -2 )(g)(g h -1 ) of T Piedras Blancas 798 2.8 E. lutescens0.10517670.72.5 4,200 E. moritziana0.057 5739.71.4 E. spicata0.05616081.92.0 Mucubaji, 969 5.4 E. schultzii0.047 9995.21.0 3,600 E. floccosa0.013 2744.80.6 Batallon 1213 9.3 E. marcana 0.038 8655.31.6 3,100 E. atropurpurea 0.018 916.30.6 Hours of transpiration were calculated by dividing the mass of available water in the pith (∆M) by the transpiration rate (T) of the entire rosette. Pith volume per unit leaf area (PV/LA) is a measure of relative capacitance

13. Temperature for 50% injury, supercooling points, and relative apoplastic water content of leaves (3-5 pressure-volume curves) of 10 Espeletia species occurring along an altitudinal gradient. Leaf water potential range was -0.4 to -0.9 Mpa (after Goldstein et al. Oecologia 68:147-152.1985) Species Elevation Supercooling 50% injury Relative apoplastic (m)point ºC ºC water content % E. lindenii2850-7.5 -6.5 7.0 E. angustifolia2850-6.6 -6.1 35.8 E. atropurpurea2850-6.4 -5.9 26.2 E. marcana3100-9.1 -8.0 20.5 E. atropurpurea3100-7.3 -8.1 19.9 E. jahnii3100-5.7 -5.6 25.1 E. schultzii3560-10.8 -10.0 16.0 E. floccosa3560-8.5 -9.3 7.3 E. schultzii4200-10.0 -11.2 3.9 E. moritziana4200-10.6 -11.3 4.0 E. spicata4200-10.0 -9.5 7.4 E. lutescens4200-10.5 -10.2 2.2

14. Relationship between cold injure temperature, and appearance of the first exhotherm for leaf tissues; n≥ 6 (modified from Squeo et al. Oecologia 86:378-382.1991) Species Temperatures ºC Cold resistance Life form Injury Freezing mechanism Espeletia moritziana-11.3-10.6Super CoolingGiant Rosette E. schultzii-12.0-11.6Super CoolingGiant Rosette E. spicata-11.3-12.8Super CoolingGiant Rosette E. timotensis-11.9-11.7Super CoolingGiant Rosette Polylepis sericea-8.0-7.5Super CoolingSmall Tree Hinterhubera lanuginosa-12.3-12.7Super CoolingShrub Hypericum laricifolium-10.9-9.4Super CoolingShrub Senecio formosus-9.3-3.5Freezing TolerancePerennial Herb Castilleja fissifolia-14.8-4.1Freezing TolerancePerennial Herb Arenaria jahnii-18.8-3.2Freezing ToleranceCushion plant Azorella julianii-10.6-3.7Freezing ToleranceCushion plant Draba chionophylla-14.8-5.0Freezing ToleranceSmall Rosette Lucilia venezuelensis-14.3-4.4Freezing ToleranceCushion plant Cold injury measured with Triphenyl-tetrazolium chloride (Steponkus and Laphear Plant Physiology 42,1423.1967 Cold resistance mechanism: difference between injure temperature (IT) and freezing temperature (FT) (Larcher 1982) IT larger than FT---> freezing avoidance by insulation IT similar to FT ---> supercooling IT lower than FT ---->freezing tolerance